MUSTteLUS L^VTS. 221 



other and most proximal branch is the one that has its ap- 

 parent origin partly from the dorsal root of Trigeminus II. It 

 runs backward, and joins the so-called ramus hyoideus facialis, 

 thus doubtless forming the lateral and ampullary sensory 

 component of the post-trematic branch of the facialis. There 

 thus remains only the ramus buccalis to be accounted for of 

 all the lateral sensory branches of the facialis, and this nerve 

 is, unfortunately, not especially described, and not even 

 indicated in any of Haller's figures. It may form part of the 

 so-called ramus maxillaris superior trigeniini, and it would 

 seem as if it must receive fibres from both of the roots of 

 Trigeminus II. That the nerve exists as an important nerve 

 is evident from Marshall and Spencer's descriptions of it in 

 embryos. 



The ramus ophthalmicus superficialis of Haller's descriptions 

 of Scyllium is thus formed of two components, a dorsal and a 

 ventral one, both of which arise from what are considered by 

 several authors as lateral sensory tracts of the brain. As in 

 Haller's descriptions, there are but two ophthalmic nerves, a 

 ramus superficialis, and a ramus profundus, the natural 

 conclusion would l)e that the two components described by 

 him in the ramus superficialis must necessarily be the united 

 portio major and portio minor of the nerve. A comparison 

 with Schwalbe's descriptions of this same fish (57, p. 187) 

 lead one, however, to strongly suspect that Haller has simply 

 repeated Balfour's mistake, and given the name profundus to 

 what is in reality the portio minor of the superficial nerve. 

 Haller's fig. 52 practically confirms this. The subject is then 

 still further complicated by Haller's statement (p. 496) that 

 in Salmo the fibres corresponding to those that form the 

 ramus profundus of Scyllium arise from the posterior instead 

 of from the anterior root of the trigeminus, thus belonging to 

 his Trigeminus II instead of to Trigeminus I. Haller attempts 

 to explain this uncomfortable fact in the statement that "bei 

 den Salmoiden und wohl auch anderen alteren Vertretern der 

 Teleostier eine Rostralwartsverschiebung vom Boden des 

 chordalen Hirnes stattfand und dass damit auch ein grosser 



